Evaluate whether or not ActiveFedora::NestedAttributes#define_autosave_association_callbacks and other method generation behaves as expected

[jrgriffiniii]

https://github.com/samvera/active_fedora/blob/master/lib/active_fedora/nested_attributes.rb#L66 seems to indicate that it does not, but there do not appear to be any breaking builds.

Coveralls reports that it is indeed covered in tests:
https://coveralls.io/builds/18480644/source?filename=lib%2Factive_fedora%2Fnested_attributes.rb#L66

[no-reply]

looks like this issue pops up when attempting to define sub-classes of AF::Base classes. the *_attributes accessor methods are lost for the inheriting class.